Studies to improve rooting uniformity of single node stem cuttings for rose are reported. We found that the variation in shoot growth in a young rose crop depended on the variation in root number of the cuttings, which, in turn, was related to the auxin concentration applied to the cutting before rooting. Instead of powder formulations, we started using low concentration auxin solutions and developed the concept of ‘hormonal time’, expressed as μM.min, to standardize the auxin uptake. In that way, it was possible to increase the efficiency of rooting and to obtain a more uniform rooting than with auxin powders. In experiments, 80-100% rooting and good bud break was observed in a range of 200-2000 μM.min. At longer hormonal times, the root number increased but bud break was inhibited. To obtain high rooting percentages approximately 1000 μM.min would be a safe guideline.